Abstract
Dilute combustion, either using exhaust gas recirculation or with excess-air, is considered a promising strategy to improve the thermal efficiency of internal combustion engines. However, the dilute air-fuel mixture, especially under intensified turbulence and high-pressure conditions, poses significant challenges for ignitability and combustion stability, which may limit the attainable efficiency benefits. In-depth knowledge of the flame kernel evolution to stabilize ignition and combustion in a challenging environment is crucial for effective engine development and optimization. To date, comprehensive understanding of ignition processes that result in the development of fully predictive ignition models usable by the automotive industry does not yet exist. Spark-ignition consists of a wide range of physics that includes electrical discharge, plasma evolution, joule-heating of gas, and flame kernel initiation and growth into a self-sustainable flame. In this study, an advanced approach is proposed to model spark-ignition energy deposition and flame kernel growth. To decouple the flame kernel growth from the electrical discharge, a nanosecond pulsed high-voltage discharge is used to trigger spark-ignition in an optically accessible small ignition test vessel with a quiescent mixture of air and methane. Initial conditions for the flame kernel, including its thermodynamic state and species composition, are derived from a plasma-chemical equilibrium calculation. The geometric shape and dimension of the kernel are characterized using a multi-dimensional thermal plasma solver. The proposed modeling approach is evaluated using a high-fidelity computational fluid dynamics procedure to compare the simulated flame kernel evolution against flame boundaries from companion schlieren images.
Original language | English (US) |
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Title of host publication | ASME 2020 Internal Combustion Engine Division Fall Technical Conference, ICEF 2020 |
Publisher | American Society of Mechanical Engineers (ASME) |
ISBN (Electronic) | 9780791884034 |
DOIs | |
State | Published - Nov 4 2020 |
Event | ASME 2020 Internal Combustion Engine Division Fall Technical Conference, ICEF 2020 - Virtual, Online Duration: Nov 4 2020 → Nov 6 2020 |
Publication series
Name | ASME 2020 Internal Combustion Engine Division Fall Technical Conference, ICEF 2020 |
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Conference
Conference | ASME 2020 Internal Combustion Engine Division Fall Technical Conference, ICEF 2020 |
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City | Virtual, Online |
Period | 11/4/20 → 11/6/20 |
Bibliographical note
Funding Information:The submitted manuscript has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory (“Argonne”). Argonne, a US Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357. The US Government retain for itself, and others acting on its behalf, a paid-up nonexclusive, irrevocable worldwide license in said article to reproduce, prepare derivative works, distributed copies to the public, and perform publicly and display publicly, by or on behalf of the Government.
Funding Information:
The submitted manuscript has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory (?Argonne?). Argonne, a US Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357. The US Government retain for itself, and others acting on its behalf, a paid-up nonexclusive, irrevocable worldwide license in said article to reproduce, prepare derivative works, distributed copies to the public, and perform publicly and display publicly, by or on behalf of the Government. This research is funded by DOE's Vehicle Technologies Program, Office of Energy Efficiency and Renewable Energy. The authors would like to express their gratitude to Gurpreet Singh and Michael Weismiller, program managers at DOE, for their support. In addition, the authors gratefully acknowledge the computing resources provided on Bebop, a high-performance computing cluster operated by the Laboratory Computing Resource Center at Argonne National Laboratory. Finally, the authors would like to thank Anand Karpatne and Doug Breden at Esgee Technologies Inc. for their technical supports and valuable discussions on the use of the VizSpark software.
Funding Information:
This research is funded by DOE’s Vehicle Technologies Program, Office of Energy Efficiency and Renewable Energy. The authors would like to express their gratitude to Gurpreet Singh and Michael Weismiller, program managers at DOE, for their support. In addition, the authors gratefully acknowledge the computing resources provided on Bebop, a high-performance computing cluster operated by the Laboratory Computing Resource Center at Argonne National Laboratory. Finally, the authors would like to thank Anand Karpatne and Doug Breden at Esgee Technologies Inc. for their technical supports and valuable discussions on the use of the VizSpark software.
Publisher Copyright:
Copyright © 2020 ASME
Keywords
- Flame kernel growth
- Nanosecond-pulsed discharge
- Spark-ignition modeling
- Thermal plasma